Art of cracking hydrocarbons



UNITED 'STATES PA TENT OFFICE.

. `ART OF CRACKING HYDROCARBONS.

Specicationof Letters Batent.

Application med March' 22, 1,917. serial No. 156,652.'

To all whom t may concern:

vBe' it known that I, JOHN W. COAST, J r.,

a citizen of the United States of America, a`

resident ofATulsa, in the county of Tulsa, State of Oklahoma,have'invented certain new and useful Improvements in the Art of CrackingHydrocarbons, of which the following is afull, clear, and exactdescription, reference 'being had tothe accompanying drawings, forming apart of this speciication.

My invention relates to improvements in the art of cracking petroleumhydrocarbons, one of theobjects being to protect cracking stills fromthe injurious effects of'cokelforming substances which tend toaccumulate on the hottest parts of the`stills. This feature of theinvention increases the eiiiciency of the cracking apparatus bycirc-ulating the coke or carbon away from the point at which heat istransmitted to the still, thus permitting then heat to be transmittedVfreely from the still to the doil, at the Y same time avoiding the.danger of overheating the metal of the still, and allowing theapparatus toremain in service for a considerable period of time withoutremoving 4the coke.

Another object is to increase the efficiency of the apparatus byforcibly circulating the relatively cool liquid to the hottest-part ofthe still. A further object is'to increase the yield by compressing gasand forcing it into the liquid contents of the still. This gas ispreferably a product of distillation recovered from the condenser`V of acracking I apparatus.

In the preferred form of the invention all of the foregoing objects areattained by conducting gas from the condenser to which the crackingstill is co nnectedy compressing such gas and forcing it into the liquidcontents of the still. t

Figure I is a diagrammatical view of a crac ing apparatus adapted i vforuse in carrying out my method.

Fig. II is an enlarged transverse section of the still taken on the lineII-II, Fig. I. Fig. III is an enlarged fragmentary view showing thedischarge pipes at the lower portion of the still.

To illustrate the invention, I have shown a still 1 arranged above aheating chamber 2, and connected by 'meansof an air cooled vapor pipe 3to a reflux condenser 4." 5

to 800o F.

i preferably in the form of designates a vapor pipe leading from thereil'ux condenser to a main condensing coil 6, from which the lowboiling point product is conducted through a pipe 7 and in to arecelving tank 8. The condensing coil 6 is Patented June 29, 1920.

To THE 'EROOEss COMPANY,

preferably arranged in a water tank 9. The 1 air cooled vapor pipe 3constitutes 'a reflux condense-Land 1t is inclined to allow Vthecondensate to flow backwardly to the still.

I have shown in particuuse in cracking high boilof distillation', such,for

The apparatus .larly adapted for ing point products example, as thedistillates or residues resulting from the distillation of petroleum.The

oil to be'treated isintroduced into the still in any suitable manner,and any desired pressure may be obtained by regulating the valve 10,preferably located in the vapor pipe 5. The pressure in the still, vaporpipe 3 and reiux condenser 4:, is preferably greater than lifty poundsper square inch, and the temperature of the contents of the stillpreferably ranges. from about 600, F. If the pressure regulating valve10 is arranged in the vapor line as herein shown, the contents of thestill will be maintained under the desired high pressure, and thecontents of the condenser 6 will be maintained under a pressure of aboutone atmosphere.

A trap, or liquid seal 11, is formed in the condensate pipe 7 toprevent. the gas from passing to the receiving tank 8. This gas ispreferably conducted through a pipe 12 and utilized to accomplishseveral desirable results, aswill be hereinafter pointed out.

13 designates a coke trap or catch basin, a false bottom ar-l ranged inthe lower portion of the still and extending from one end of the stillto the other. .Discharge pipes 14 and 15, arranged withinthe still belowthe false bottom 13, are provided with transverse discharge ports 16.These discharge pipes are arranged longitudinallyA of the still and theypreferably extend approximately from one end of the still to the other.The discharge ports 16 are so formed that the fluid discharged therefromwill vHow from the still bottom in opposite directions. A conductor 17,leadingl from a compressor 18, is provided with branch pipes 111 and 15for conducting Huid to the discharge pipes 14- and 15. Valves 19 (Fig.I) arranged in the pipes Mand 15may beregulated to control the flow offluid to the discharge pipes 14@v `and 15 at the lower portion o f thestill; The valves 19 may be operated alternately to circulate'the liquidat the bottom of the still in opposite' directions. When the fluid isdischarged through the pipe 14, a circulation will be created betweenthe false bottom 13 and the hottest part of the still, thus causing thecole-forming substance to flow transversely of the still and finallysettle upon the false bottom 13 whereby it is held and prevented fromreaching the main bottom. The direction of flow may be reversed byshutting off the supply of fluid to the pipe 14, and permitting thefluid to flow through the pipe 15. thismanner I prevent the coke fromaccumulating at the hottest part of the still, at the same time forciblycirculatingthe relatively cool portions of the liquid to the hot stillbottom.

In the preferred form of theinvention, I utilize a gas for circulatingthe liquid contents of the still, and this gas is preferably a productof distillation resulting from a cracking process. This may beconveniently accomplished by conducting gas from the condensate pipe 7,through the pipe 12, into a pump 20, and thence through a conductor Bycirculating the liquid iny to the arcuate ,bottom of the still `tovaporize the oil, conducting lvapor from the still to a condenser,maintaining the'contents of the still under pressure, vcompressing gasand discharging s treamsof the gas trans; versely` of the arcuate.

which heat is transmitted to the oil, so as to force coke-formingsubstance across saidarcuate bottom, and catching'thecoke-formingsubstance deflected from said arcuate bottom to vprevent it fromreturning to the poiit at ywhich heat is transmitted to the stil v Intestimony that I claim the foregoing I hereunto affix my signature.

JOHN

horizontal bottom through w. ooAsT, Ja

